I have never been banned, I got my 3ds around 2015 and I modded in early 2016, I always have spottpass disable, and recently got my friend list on, I erase the majority of the homebrew cias and use rosalina to enter to the homebrew launcher, I normally use ftp to transfers files as well jk save manager in .3dsx, I have b9st since July last year I think, I normally don't play multiplayer games and only use for pokemon shuffle check in, besides I'm been playing in coop nsmb2, I normally left the wireless off, I think they collect some data in a determined time, after that they blacklist the 3ds and start the banning process after month have Passed, it might explain why people previously banned got banned again even though they have privated seeds